Now, those researchers have determined why they were able to trounce the quantum computer at its own game. Their answer, presented on October 29 in Physical Review Letters, reveals that the quantum problem they tackled — involving a particular two-dimensional quantum system of flipping magnets — displays a behavior known as confinement. This behavior had previously been seen in quantum condensed matter physics only in one-dimensional systems.

This unexpected finding is helping scientists better understand the line dividing the abilities of quantum and classical computers and provides a framework for testing new quantum simulations, says lead author Joseph Tindall, a research fellow at the CCQ.